#include <iostream>
#include <math.h>
using namespace std;
int x[20], n, k;

bool isprime(int n) {
	int s = sqrt(double(n));
	for (int i = 2; i <= s; i++) {
		if (n % i == 0)
			return false;
	}
	return true;
}

int rule(int choose_left_num, int already_sum, int start, int end) {
	if (choose_left_num == 0)
		return isprime(already_sum);
	int sum = 0;
	for (int i = start; i <= end; i++) {
		sum += rule(choose_left_num - 1, already_sum + x[i], i + 1, end);
	}
	return sum;
}

int main() {
	cin >> n >> k;
	for (int i = 0; i < n; i++)
		cin >> x[i];
	cout << rule(k, 0, 0, n - 1);
	return 0;
}